Today we wish American boxer Muhammad Ali, whose achievements inside and outside the ring made him one of the most remarkable personalities in 20th century sports, a happy birthday as he turns 69. Though cutting a controversial figure during his boxing days when he is one of the most recognizable people on the planet, he is today one of the most beloved figures in the sporting world and lends his celebrity to many worthwhile causes, notwithstanding his severe physical decline as a result of Parkinson disease.

Born Cassius Marcellus Clay, Jr., the man who would become Muhammad Ali began his professional boxing career with ample demonstration of his talents as a showman (he dubbed himself “the Greatest” used poetry such as “float like a butterfly and sting like a bee” to describe his abilities), but boxing purists questioned his ring skills. That perception changed radically with his first title shot. As Thomas Hauser, author of The Black Lights: Inside the World of Professional Boxing and Muhammad Ali: His Life and Times, describes in his entry for Britannica:

On Feb. 25, 1964, Clay challenged Sonny Liston for the heavyweight championship of the world. Liston was widely regarded as the most intimidating, powerful fighter of his era. Clay was a decided underdog. But in one of the most stunning upsets in sports history, Liston retired to his corner after six rounds, and Clay became the new champion. Two days later, Clay shocked the boxing establishment again by announcing that he had accepted the teachings of the Nation of Islam. On March 6, 1964, he took the name Muhammad Ali, which was given to him by his spiritual mentor, Elijah Muhammad.

Ali dominated the heavyweight division during his three-year reign as champion, amassing a string of brilliant title defenses. It was then boxing authorities did what no fighter could do in the ring. As Hauser relays:

[O]n April 28, 1967, citing his religious beliefs, Ali refused induction into the U.S. Army at the height of the war in Vietnam. This refusal followed a blunt statement voiced by Ali 14 months earlier: “I ain’t got no quarrel with them Vietcong.” Many Americans vehemently condemned Ali’s stand. It came at a time when most people in the United States still supported the war in Southeast Asia. Moreover, although exemptions from military service on religious grounds were available to qualifying conscientious objectors who were opposed to war in any form, Ali was not eligible for such an exemption because he acknowledged that he would be willing to participate in an Islamic holy war.

Ali was stripped of his championship and precluded from fighting by every state athletic commission in the United States for three and a half years. In addition, he was criminally indicted and, on June 20, 1967, convicted of refusing induction into the U.S. armed forces and sentenced to five years in prison. Although he remained free on bail, four years passed before his conviction was unanimously overturned by the U.S. Supreme Court on a narrow procedural ground.

When he returned to the ring in 1970, he was a slower, more wary fighter. But he was also savvier, integrating techniques like the “rope-a-dope” into his arsenal. He proved the better of younger, arguably more powerful opponents like George Foreman (at the “Rumble in the Jungle”) and Joe Frazier (at the”Thrilla in Manilla”), and became the first fighter to claim the heavyweight crown on three separate occasions.

Ali retired from the ring in 1981 with a 56 wins (37 by knock out) and 5 losses, but the blows to his head took their toll, slurring speech, slowing movement, and causing other symptoms characteristic of Parkinson syndrome